How to Measure Signal Strength
Cell signals change constantly as new towers are installed by carriers, construction projects become implemented, seasons transition, and as devices age and technology changes, for example. Your signal strength is in constant flux as you transition to different locations and experience a multitude of environmental changes throughout each day.
What about signal bars?
The bars shown in the notification panel of your cell phone are not very accurate. They give you a general idea of your signal strength, but not a quantifiable reading. Carriers can display any number of bars in your notification panel regardless of actual signal strength. You can do more than check your bars to measure signal strength on your cell phone! Here are a few quick tricks that you can use to measure your cell phone signal or get more information on your cellular coverage.
Measure Signal Strength in Numbers (dBm)
Signal strength received from a cell tower is measured in decibel-milliwatts and represented by the unit dBm, which is a unit of electrical power in decibels (dB) in reference to 1 milliwatt (mW). dBm is a more advanced, quantifiable measurement of signal strength.
The scale runs from -150 to 0 dBm, and a number closer to zero indicates stronger cell signal. -50 to -95 dBm is a common, working signal. If your reading is below -95 dBm, say -105 dBm, then you probably have a very weak and unreliable cell signal. My dBm reading is currently -115, which means I probably need a cell booster! If you measure signal strength at -95 dBm and install a cell booster with +30 dB of gain then your signal strength will improve to -65 dBm upon installation. So, how can you measure signal strength in dBm on your phone?